The Comprehensive Sickle Cell Center of Columbia University includes the scientific resources of the College of Physicians and Surgeons and the clinical resources of its 3 main hospitals: Presbyterian, St. Luke's/Roosevelt and Harlem Hospital. The Center will continue to provide excellent clinical care, screening, genetic counseling, prenatal diagnosis and education to the community of the upper part of Manhattan, where the largest concentration of patients with sickle cell diseases (SCD) and their families live. The Center will include 8 research units, 3 clinical units (one at each hospital) and 2 core units. The research units will be exclusively dedicated to research; the clinical units will also provide clinical care, screening and education. The areas of research will be the following: Transfer of the beta-globin gene, Production and study of transgenic mice containing HgbS, Interactions and aggregation of HgbS molecules, Erythropoietic precursors in SCD, Microvascular function in SCD, Cerebro-vascular circulation in SCD, Neurological involvement in SCD, Bone marrow transplantation in SCD. Two core units will also provide molecular biology analysis, prenatal diagnosis, hematological testing, data management, statistics and administration. The goal of the Center is to foster improved knowledge in the area of sickle cell diseases and to provide an environment where the advances in the field generated by the various research projects may be brought immediately to the patients.